The present invention pertains to Integrated Services for Digital Networks (ISDN) and more particularly to circuitry for converting data in an ISDN compatible format and to data compatible with T-carrier formats and vice versa.
In general, an Integrated Services Digital Network is a system which provides end to end digital connectivity to a wide variety of services by users having multi purpose user network interfaces. ISDN systems provide voice switching, packet data switching, signalling networking and wideband networking capabilities.
ISDN systems typically provide for data transmission and reception employing a particular format. Usually, this format is incompatible with T-carrier data formats. The data transmission rates of ISDN systems and T-carrier facilities are typically in the megabit per second range. Conversion of data from the ISDN format to the T-carrier format and vice versa must be done rapidly. In addition, circuitry must operate both for receiving and transmitting data simultaneously.
Further, the reformatted data must be stored in contiguous memory locations. Any unused information must be removed from the data stream without destroying any contiguous valid data. The contiguity of data within the memory assures easy and rapid output by the transmission system.
Therefore, it is an object of the present invention to provide a high-speed data format conversion circuit for dynamically converting between T-carrier format and an ISDN format.
It is another object of the present invention to provide high-speed circuitry for generating proper framing for ISDN and T-carrier formatted data.